The present invention relates to a windshield wiper arrangement, and more particularly to an improved windshield wiper arrangement for use in automotive vehicles.
In the prior art, windshield wiper arrangements usually comprise a wiper arm and/or an intermediate arm which are mechanically linked and connected to a power unit for swinging movement back and forth across a windshield, a wiper blade which is essentially a rubber squeegee, and a carrying arm which receives and supports the wiper blade and which also is pivotally connected to the wiper arm.
One well-known windshield wiper construction connects an elongated U-shaped carrying arm with a wiper arm by means of a rivet. The rivet shaft is inserted through lateral openings provided in the sidewalls of the U-shaped carrying arm, and then the leading end of the rivet is peened over. The rivet-type connection, however, is not sufficiently secure, because the inner circumferential surface of the lateral openings is inadequate to prevent the rivet from rotating therein, especially after a period of use.
In order to make the connection between the arms more secure and safer to use, stepped rivets, i.e. rivets having portions of different diameters, have been employed in specially-designed openings in the sidewalls. However, such arrangements have only proven effective for short periods of use. Inevitably, the clamped connection at the sidewall between the shoulder of the stepped rivet and the head made after riveting loosens. This effect is worsened, of course, with continuous usage of the windshield wiper. A detached connection is further disadvantageous because it causes excessive chattering of the wiper blades against the windshield and because it exposes more surface area to be corroded. Moreover, the related expenses of making the stepped rivet and of providing different holes of different diameters in the sidewalls makes this prior-art arrangement too uneconomical.
Still another prior-art windshield wiper arrangement connects the wiper arm to the carrying arm by forming two sleeve-like attachments on the sidewalls of the carrying arm which project outwardly and normally of the elongation of the carrying arm. The wiper arm, however, must have two coupling members on both of its sides to surround the two sidewalls of the carrying arm and be inserted into the two sleeve-like attachments. Not only is such an arrangement unsightly and costly, but, in addition, it utilizes a great amount of space. It will be appreciated that such an arrangement will interfere with the proper seating of the wiper blades.
Yet another prior-art arrangement tries to avoid this aforementioned disadvantage by aligning the two sleeve-like attachments formed on the two sidewalls inwardly towards each other. However, in that case, the rear side of the carrying arm -- i.e. the closed end of the U-shaped configuration -- must be provided with a hole to permit accessability of the wiper arm to the connection. The presence of the hole, however, causes the further disadvantage that it weakens the rigidity of the carrying arm, and especially the stiffness and the strength of the sidewalls. In operation, such a prior-art arrangement is particularly prone to deformation since the wiper arm will transmit most of its energy to the weakest point of the carrying arm. The sleeve-like attachments not only frequently are deformed, but the coupling members on the wiper arms often become detached making the entire arrangement useless.